US6946565B2ExpiredUtilityPatentIndex 89
Process for the preparation of an indole derivative
Est. expiryJul 16, 2018(expired)· nominal 20-yr term from priority
C07D 209/42
89
PatentIndex Score
22
Cited by
11
References
11
Claims
Abstract
A process for the preparation of methyl 2-(3-chloropropoxy)-indole-3-carboxylate, which comprises reacting a 3-chloro-3-carboxylate indole compound with 3-chloropropanol in the presence of an acid having a pKa of from 0 to 2.
Claims
exact text as granted — not AI-modified1. A process for the preparation of methyl 2-(3-chloropropoxy)-indole-3-carboxylate, namely the compound of formula (B):
which process comprises reacting a compound of formula (C)
with 3-chloropropanol in the presence of an acid having a pKa of from 0 to 2, wherein the acid is trichloroacetic acid, dichloroacetic acid and/or trifluoroacetic acid.
2. A process as claimed in claim 1 in which the reaction is effected in an organic solvent.
3. A process as claimed in claim 2 in which the organic solvent is dichloromethane or chloroform.
4. A process as claimed in claim 3 wherein the reaction is effected using a catalytic amount of the acid.
5. A process for the preparation of methyl 2-(3-chloropropoxy)-indole-3-carboxylate, namely the compound of formula (B):
which process comprises reacting a compound of formula (C)
with 3-chloropropanol in the presence of an acid having a pKa of from 0 to 2, wherein the reaction is effected in an organic solvent at a temperature in the range −20° C. to +10° C.
6. A process as claimed in claim 5 in which the acid is trichloroacetic acid, dichloroacetic acid and/or trifluoroacetic acid.
7. A process as claimed in claim 5 in which the acid is trichloroacetic acid.
8. A process as claimed in claim 5 in which the organic solvent is dichloromethane or chloroform.
9. A process as claimed in claim 6 in which the organic solvent is dichloromethane or chloroform.
10. A process as claimed in claim 5 wherein the reaction is effected using a catalytic amount of the acid.
11. A process as claimed in claim 9 wherein the reaction is effected using a catalytic amount of the acid.Cited by (0)
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